For the past few years, the difference between an MGM movie and a United Artists movie has been a matter of semantics. Shortly after MGM bought UA in 1980, studio chief David Begelman began overseeing all productions of both studios, and his successor Frank Yablans continued the tradition of simply assigning one logo or the other to each new film, seldom for any particularly important reason. But that changed this week, as MGM/UA officially split its moviemaking activities into two separate production units that will share distribution and marketing departments.

Certainly, the company could use some shaking up -- MGM/UA has had two consecutive poor earnings reports, with the reasonable but not overwhelming success of the expensive "2010" its only recent bright spot. Under the new arrangement, Yablans will continue to oversee MGM, and Alan Ladd Jr. will come in to head up UA. (Ladd has had box-office troubles of his own lately -- his long-term production contract with Warner Bros. was canceled last spring after the lackluster showing of most of his productions, which included such critical successes as "The Right Stuff" but only one bona fide hit, the lowbrow "Police Academy.") MGM/UA chairman and chief executive Frank Rothman says the new arrangement will make the two companies fully competitive. That's an understatement, say industry veterans, who foresee a pitched battle for the biggest share of the MGM/UA pie . . .

The biggest hit in European theaters these days is, of all things, Francis Coppola's "The Cotton Club." Helped by the director's overseas status and a revised ad campaign that downplays the period elements and emphasizes the fast-paced mixture of dancing and shooting, the film was France's top-grossing movie in its first week, picking up a startling $15,000 per-screen average. (In the United States, its first-week average was $5,200.) Bringing out crowds in Europe's worst winter in years, the film set a new house record in Paris -- breaking the record established by Coppola's "Apocalypse Now." And it did nearly as well in Italy . . .

Television stations, beware: Franco Zeffirelli has won a lawsuit against an Italian TV station that inserted too many commercials into an airing of the director's "Romeo and Juliet." A Milan judge ruled that the Antenna Nord station violated Zeffirelli's moral rights by interrupting the film 18 times -- but that Zeffirelli wasn't entitled to damages . . . The TV series "The Untouchables" may soon wind up on the big screen, if Paramount's negotiations with writer Oscar Fraley and the Eliot Ness estate pay off . . . Universal, meanwhile, is planning to take a couple of Alfred Hitchcock's TV shows and turn them into a feature film, a la the earlier treatment of "The Twilight Zone". . .

The Broadway musical "Baby" may follow in the footsteps of other stage hits: Producers Larry Thurman and David Foster have purchased the film rights to the play about three unexpectedly expecting couples. But "Baby," which picked up seven Tony Award nominations, may make an atypical transition. Thurman and Foster are now looking for a screenwriter for the Embassy Pictures project and, says Thurman, "assessing whether to make 'Baby' as a nonmusical" . . . Thurman and Foster are also producing "2010" director Peter Hyman's next film, an action comedy set in Chicago and titled "Running Scared" . . .

It's the future, California has been officially declared crazy and fenced off from the rest of the United States, and warriors from Scientology and est are battling for control of the state. It sounds ridiculous to those of us who live out here, but that scenario has excited the interest of a London-based, self-described "strange mix of doctors, lawyers and royalty" -- they're putting up the $8 million needed to shoot "California Crusade," written and directed by "The Last Starfighter" director Nick Castle. One of the provisions of the anonymous financiers is that the film be shot entirely in England. Now that sounds crazy . . .